Weight safety device.



A. E. NEWTON.

WEIGHT SAFETY DEVICE.

APPLICATION FILED APR. 12, 1911.

1 .01 9,517. Patented Mar.5, 1912.

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ALBERT E. NEWTON, 0F WORCESTER, Iv'IASSACI-IUSETTS, ASSIGNOR TO PRENTICEBROS. COMPANY, A CORPORATION OF MASSACHUSETTS.

WEIGHT SAFETY DEVICE.

To all whom it may concern:

Be it known that I, ALBERT E. NEWTON, a citizen of the United States,residing at \Vorcester, in the county of lVorcester and State ofMassachusetts, have invented a new and useful l/Veight Safety Device, ofwhich the following is a specification.

This invention relates to a weight safety device.

The principal object of the invention is to provide a constructionwhereby upon the breakage of a chain which supports a counter-weightusedon a machine tool, the counter-weight will be held from dropping, thuspreventing serious accidents to the ma chinery.

The invention involves the use of means connected with the supportingchain or the like which when released by the breaking of the latter willautomatically operate to clamp the weight in position and prevent itsfall.

The invention also involves iniprovements in details of construction aswill appear hereinafter.

Reference is to be had to the accompanying drawings in which Figure 1 isan elevation of a weight safety device constructed in accordance withthis invent-ion applied to a machine tool. Fig. 2 is an elevation of thesame at right angles thereto, and Fig. 3 is an elevation similar to Fig.2 with the weight removed and showing the parts in looking position.

The invention can be applied to upright and radial drills and to othermachine tools in which a heavy operating part has to becounter-weighted. In the form shown, the invention is illustrated asapplied to the frame 10 of an upright drill in which the quill 11 slidesvertically and is connected with a countenweight 12 by a chain or otherflexible connection 13 passing over sheaves 14. The parts so farnumbered are common in this class of machines. Instead of connecting thechain directly with the weight, however, the weight is provided with aframe or brackets 15 extending upwardly and supporting a sheave 16 underwhich the chain passes. The end of the chain is connected with a hook 17mounted on an arm 18 on a shaft 19 mounted on bearings on the frame orbrackets 15. Also on this shaft is another arm 29 which serves as a stopin the Specification of Letters Patent.

Application filed April 12, 1911.

position shown in Fig. 2, so that the chain Patented Mar. 5, 1912.

serial No. 620,562.

securely holds the weight. Under the arm 29 is a spring 20 which whenthe chain breaks, pushes the arm up, turns the shaft and swings the hookdown. This turns an eccentric clutch 21 fixed to the shaft so as tobring its teeth into engagement with the teeth of a rack 22. The fartherthe spring swings the shaft around, the more efliciently will the clutchengage the rack to prevent the descent of the weight. The engagement ofthe clutch with the rack tends to further swing the former around intoclutching position. This clutch is shown as having a series of clutchteeth 23 mounted on a curve gradually receding from the center so as toprovide for more eflicient action as the weight tends to descend.

While I have illustrated and described a preferred embodiment of theinvention and shown it as applied to a drill, I am aware that it can becarried out with modifications in details of construction and that itcan be applied to other machine tools without departing from the scopeof the in vention as expressed in the claims. Therefore, I do not wishto be limited to this particular application of the invention or to allthe details of construction as shown and described, but

hat I do claim is 1. In a device of the character described, thecombination of a counter-weight, a sheave journaled thereon, a flexibleconnection depending from above and passing under the sheave, a shaftjournaled on the counter-weight and having an arm projecting upwardly atone side of the sheave, the end of said flexible connection beingconnected with said arm after passing under the sheave, an eccentricclutch on the shaft for engaging the frame, and means whereby when thesupport of the flexible connection is removed said shaft will be turnedto bring said eccentric clutch into operation.

2. In a device of the character described, the combination of a verticalrack having teeth, a countenweight slidable up and down the rack, asheave journaled on the counterweight, a shaft on the counter-weighthaving two arms thereon, a flexible supporting member passing under thesheave and connected with one arm at one side of the sheave, a springsupported on the counterweight and bearing on the other arm and tendingconstantly to turn the arm andv nected with said hook after passingunder the sheave, a. clutch connected with the arm for engaging theframe, and means whereby when the support of the flexible connection isremoved said clutch is brought into operation.

In testimony whereof I have hereunto set my hand, in the presence of twosubscribing witnesses.

ALBERT E. NEVTON.

Vitnesses FRED K. HENDRIoKsoN, C. FORREST WVEssoN.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington. D. C.

